So I'm going to be attempting my first indoor grow. Trying to germinate some seeds with spring water now. I purchased a cheap electronic PH tester from Amazon and have come to the conclusion it is junk and returned it. Definitely don't want to spend money on a good one as I'm an occasional grower and they seem to high maintenance fro me anyways. I ended up getting a general Hydroponics PH control kit that has PH up and down, along with the drops to check for PH. I did some testing of my water with it and it's definitely not the most accurate way to test.
So at my home I have regular well water, softened well water and RO water we use to drink. I heard the softened water is definitely a no go so I haven't even tested it. My RO water tested out about 6.5. The unsoftened water was at 7 to 8 but after adding 20 drops of ph down to 2 quarts of water, it brought the ph down to about 6.5.
TDS I tested on the RO water was 24 and the unsoftened water was at 350. I also tested spring water and it was around 250.
I really want to use the regular unsoftened water for my plants as the RO is slow and hard to get in the area I'm growing. I realize I need to PH the water after I use nutrients but I won't be using nutes for most of my veg cycle as I'm growing in a combination of FFOF, FFHF, Manure, and perlite blend which will give the plants plenty of nutrients to start. We'll have a lot of snow here for the winter so I'm sure I can bring that in and melt it down in buckets for water. Rain water is going to be harder to collect as the gutters dump into pipework into the ground and prefer to not mess with it in the winter months.
Is it going to be OK to use my well water for watering by adjusting PH or do I have way too much TDS in the water? Maybe use a blend of snow melt and well water?
Start by NOT listening to any of the above posts.
How about I make this easy and simple to understand?
Lets start with TDS or
Total Dissolved Solids. A TDS meter, measures in Parts Per Million or ppm.
In general growing terms. You should not use water's that have a ppm of over 150. You are NOT sure just what any of those ppm's are. Generally they are dissolved minerals, like Ca compounds. There will be Si (silica) in there
BUT, well waters and spring waters can
easily contain Nitrogen, Phosphorus and Potassium compounds. In cities, this comes from lawn fertilizers and in rural area's in wells from farm runoff...
This is why I say you just don't
know whats
in those well waters....Or "Spring" waters for that matter...
Softened water
is a big NO, NO...
period.
Now then, about that 150 ppm thing. It is safe to use a water from a well or a "spring" that meters 150 or less. This would be safe basically no matter what the mineral or NPK spread would be of that water. The NPK part might make it a job to dial in but, will work.
You have RO! BINGO the use of RO.... You list your RO out put at 24 ppm. For me, that's the time I start monitoring my inline ppm meter for it to start rising in value as it goes over time...The faster the ppm # rises. The more you are getting to need to change that membrane!
Lets talk about RO water and growing a minute. RO water has been stripped of everything as far as dissolved solids goes (never mind the 24ppm, we're talking about RO water in general). You have removed the waters natural buffers to pH values.
This water is now only effected by the amounts of dissolved Co2 gas in it as far as being effected by pH (potential Hydrogen) value. Now someone might say that dissolved o2 has the same reverse effect on pH but not so fast....Co2 has the real important effect on it. UNTIL you begin to "add" mineral compounds
back to the water.
In hydro growing. Once you have stripped water of it's dissolved solids. You are more then likely, going to have Ca'Mg issues and your solution mix's will be rather pH unstable....Your going to be chasing pH and it won't stay at your set point well (Hydro pH does rise over time naturally).
This is why you will see it being recommended to use a Ca/Mg product to add a "buffer" back to the RO water. This is
best done by using a
Calcium carbonate based Ca/Mg product for pH control.
Some one might say that type of Ca isn't as available to your plant. True
but it also contains half the nitrate compounds and is more effective at holding that pH value over time.
How about soil and RO?
I use it ALL THE TIME. I run organic, water only soils I build. I do not pH my in going water! Simply water the plants with my RO and walk away....
I add no Ca/Mg compounds to my RO to start. I'm organic soil I don't need to! There is enough in the soil already!
NOTE: If you use FF Ocean Forrest. Add a good fat handful of Dolomite Lime to the whole bag and mix it in well (Dump it out in a kiddie pool and sprinkle the lime over the whole bag and mix it in the pool.) FFOF soils have a tendency to not have enough Ca/Mg to run the whole grow out....
When I build my own soils. I do not use Dolomite lime in my mix's very often. The reason being is that DOLO has high amounts of Mg in it. For most growing of cannabis, you won't need that much.
I prefer oyster shell powder and pulverized egg shells (un-roasted). Only special soils made for some strains that are real Mg hogs get any Dolo, and even then the amounts are small...
So, when you go to start growing. Skip the practice of adding a "buffer" to your RO.
Now a word on pH and organic growing..
To be real, forget about it! If your keeping a good healthy bio heard in your soil....The soil will self pH! The whole grow long.
You might add some living bio's about every month by using some AACT (Actively Aerated Compost Tea) I use only simple Bio tea formula's and
NEVER add any Kelp meal to my tea brewing. Kelp meal will severely lower the living bio counts when brewing it in a tea!
This stuff is stupidly simple to make and use. Formula's are all over the net..
Here is a NICE link that does not push some product or another...
http://www.gardeningwithmicrobes.com/aact.shtml
Best living bio counts come it between 36 and 48 hrs of brewing, so keep that in mind.
Back to pH facts.
In nature it rains. This rain makes the now wet soil drop in pH by around a whole point. NPK nutrients (and minerals) are available to the plant at differing pH values. This is natures way of having those things available to your plant in amounts the plant needs.
The same is true for when you water a house plant or any container plant. You water or feed and the pH of the soil drops. As the soil dry's back out,,,,the pH rises back to the plants happy zone.
I should note here that plants kind of "set" the pH in the soil surrounding it. To where it's comfortable.
Now you need to know that over watering can keep the soils pH too low and that in turn will create a pH issue that will begin to block or "lock out" nutrients from the plant...
So, don't keep your soil too damp for too long....
Simple way to know when to water a container plant?
Water it and pick it up. Notice how heavy it is. When that plant dries out to needing a feeding/watering again. It should weight about 1/3 or less of what it did when it was wet. If the plant droops from needing water...No biggie, just water it more/more often...
Review and simplify:
For you. Use the RO. Add nothing but any "feed" your going to use to it and water.
Don't over water.
Use a little AACT every 3-4 weeks....
Be happy!
GOOD LUCK!
